A thickening in the walls of the airways may be a result of scar tissue (e.g., permanent damage) or a potentially treatable tissue irritation. The airways in the lungs of a patient may be examined for anatomical defects using standard computed tomography (CT). However, it may not be possible to distinguish scar tissue from tissue irritation using a standard CT image alone.
The technique of dual energy computed tomography (DECT) may be used to obtain functional information from images of a patient's airways. In DECT, an image of a patient who has been injected intravenously with a contrast agent (e.g., iodine) may be captured using two different energy sources (e.g., a high-energy source and a low-energy source). In the dual energy images thus obtained, the iodine concentration may be differentiated from other materials (e.g., water and tissue). Since the intravenous iodine is in the blood, a determination of iodine concentration may indicate whether a thickened area results from scar tissue or from increased blood flow indicative of inflammation.
The resultant iodine map generated from DECT provides a complete volume of the patient including information that may be extraneous to the diagnosis and/or evaluation of an airway disease (e.g., chest wall, blood vessels, parenchyma, etc.). This extraneous information may reduce the overall efficacy and convenience of using a DECT-derived iodine map in a clinical and/or research environment.